Instructions

• Preheat oven to 180 °C (360 °F). Line a 20 × 30 cm (8 × 12 in) baking tray with parchment paper.
• Melt 30 g butter over low heat and set aside to cool.
• In a bowl, combine 2 tbsp flour and 2 tbsp cocoa powder; set aside.
• In a large bowl, whip 3 eggs with a pinch of salt and 4 tbsp sugar until tripled in volume and light.
• With the mixer on low, add the cooled melted butter to the whipped eggs and mix 10 seconds. Turn off the mixer.
• Gently fold the dry flour–cocoa mixture into the egg mixture using upward movements until just combined.
• Pour the batter into the prepared tray, level the surface, and bake 25 minutes or until a toothpick inserted into the center comes out clean. Transfer the cake to a cooling rack and cool completely.
• While the cake cools, make the cocoa syrup: in a small saucepan combine 50 g sugar and 20 g cocoa powder with 150 ml hot water. Heat just until the sugar dissolves, stir, then remove from heat and let cool to room temperature.
• When the cake is completely cool, slice it horizontally into two even layers. Place one layer back in the lined baking tray (this will be the bottom).
• Lightly brush or spoon some of the cooled cocoa syrup over the bottom cake layer to moisten it. Cover the top cake layer with a clean towel to keep it moist.
• Prepare the chocolate cream: soak 3 sheets of gelatin in cold water until soft (about 5–10 minutes), then drain and squeeze out excess water.
• In a small saucepan, heat 100 ml milk with 100 ml whipping cream over medium heat until almost boiling; remove from heat. Add 200 g 70% dark chocolate (broken into pieces) to the hot liquid, let sit 2 minutes, then stir until smooth.
• Stir in 1 tbsp coffee and 1 tsp vanilla extract. Add the drained gelatin sheets and stir until fully dissolved. Transfer the chocolate mixture to the refrigerator and chill until thickened but still spreadable (about 1 hour).
• Whip 200 ml whipping cream with 1 tsp powdered sugar to firm peaks. Fold the whipped cream into the cooled chocolate mixture with gentle upward movements until homogenous.
• Spread the chocolate mousse evenly over the prepared bottom cake layer. Place the reserved top cake layer on top, press gently to level, and lightly drizzle more cocoa syrup over the top (just enough to moisten). Cover with cling film and refrigerate until the chocolate layer is set (about 1 hour).
• Prepare the dulce de leche layer: soak 1 sheet of gelatin in cold water until soft, then drain and squeeze out water.
• Roast 100 g hazelnuts in the oven at 180 °C (360 °F) for 10 minutes. Let cool, then chop coarsely.
• Heat 50 ml milk to almost boiling, remove from heat and stir in the drained gelatin until dissolved. Gradually whisk in 300 g dulce de leche until smooth. Stir in the chopped hazelnuts.
• Pour the dulce de leche–hazelnut mixture over the chilled chocolate layer, smooth the top, cover with cling film, and refrigerate until set (about 1–2 hours).
• Prepare the mixed-berry mousse: soak 2 sheets of gelatin in cold water until soft, then drain and squeeze out water.
• In a saucepan, combine 200 g berry mix, 2 tbsp sugar, and 50 ml water. Cook over medium heat, bring to a boil, and simmer about 10 minutes until the fruit softens. Strain the mixture through a fine sieve, reserving the liquid and discarding solids.
• Stir the drained gelatin into the hot berry liquid until dissolved. Refrigerate the liquid until it thickens slightly (it should be partially set but still pliable).
• Whip 300 ml whipping cream with 1 tbsp powdered sugar to soft–medium peaks. Fold the whipped cream into the chilled berry liquid using gentle upward movements to form a mousse.
• Spread the berry mousse evenly over the set dulce de leche layer, smooth the top, cover with cling film, and refrigerate until firm (about 1–2 hours).
• Prepare the raspberry glaze: soak 2 sheets of gelatin in cold water until soft, then drain and squeeze out water.
• In a saucepan, combine 200 g raspberries, 2 tbsp sugar, and 50 ml water. Bring to a boil and simmer for 6 minutes. Pass the mixture through a fine sieve into a bowl, discarding seeds.
• Stir the drained gelatin into the hot raspberry liquid until dissolved. Let the glaze cool at room temperature until it thickens slightly (about 20–30 minutes) but is still pourable.
• Pour the raspberry glaze slowly and evenly over the chilled cake, smoothing gently with a spatula if needed. Refrigerate the assembled cake overnight to fully set before serving.